Is breast cancer from Sub Saharan Africa truly receptor poor? Prevalence of ER/PR/HER2 in breast cancer from Kenya

Objectives: Studies on ER/PR/HER2 in breast cancer from Sub Saharan Africa (SSA) are fraught with inconsistencies in the prevalence of hormone receptor status. In Kenya, ER/PR/HER2 for breast cancers is not part of routine assessment and available in only three to four centers across the country. Variability in methodology and interpretation makes comparison between data difficult. Our aim was to accurately determine the prevalence of ER/PR/HER2 using standardized techniques and double reporting. Prognostic tumor parameters were also correlated with clinical features and receptor status. Materials and methods: Consecutive invasive breast cancers (IBC) accrued between September 2011 and December 2012 were analyzed at Aga Khan University Hospital, Nairobi (AKUHN). Tumor blocks were stained for ER/PR/HER2 on an automated platform. Double reporting of ER/PR/HER2 was done using the Allred system and the ASCO/CAP guidelines respectively. Results: A total of 301 cases of IBC were analyzed for pathology and ER/PR/HER2. The age range of patients was 19-94 years with a median of 47.5 years. Invasive ductal carcinoma (NOS) was the most common histologic type (84.2%). ER positivity was seen in 72.8%, PR in 64.8% and HER2 in 17.6% of all cases. Triple negative breast cancers (TNBC) constituted 20.2% of the cases. There was a significant association between receptor status and histologic grade (. p < 0.001) and statistically significant trend of increasing pathological stage of tumor (pT) associated with TNBC (. p = 0.020). Conclusions: We present a definitive prospective analysis of ER/PR/HER2 from a single center and demonstrate that prevalence of receptor status from SSA is comparable with that in the West.